Quenching machine



Feb. 23, 1965 o. F. BAUER ETAL 3,170,975

QUENCHING MACHINE Filed April 13, 1961 2 Sheets-Sheet l INVENTORS OLIVER F. BAUER BY ALVIN W. SNOOK flzwF/Tmx ATTORNEY Feb. 23, 1965 o. F. BAUER ETAL 3,170,976

QUENCHING MACHINE 2 Sheets-Sheet 2 Filed April 13, 1961 IIIIII:

FIG. 4

United States Patent N 3,170,976 QUENCHING MACHINE Oliver F. Bauer and Alvin W. Snook, Rochester, N. assignors to The Gleason Works, Rochester, N.Y., a corporation of New York Filed Apr. 13, 1961, Ser. No. 102,745 6 Claims. (Cl. 2666) The present invention relates to quenching machines for gears and similar articles, and particularly to improvements in such machines of the general kind disclosed in our co-pending application Serial No. 40,012, filed June 30, 1960.

In such a machine the gear is initially quenched while clamped between upper and lower dies, and then, while kept immersed in quenching liquid, is transferred to a quenching tank at a lower level, where it is cooled to a safe handling temperature, preferably less than 100 C. Keeping the gear immersed inhibits formation of scale and, where the quenching liquid is inflammable, is an important safety measure. In order to eliminate damage to the gear by impact with the machine structure or with other gears during transfer to the tank, while it is still hot enough to be relatively soft, a work handling mechanism has heretofore been provided which physically holds the gear throughout its transfer from the lower die to a conveyor in the tank. The primary object of the present invention is to simplify the work handling mechanism while still protecting the gears from damage by impact.

According to one aspect of the invention the machine comprises a tank for coolant liquid, upper and lower dies adapted to open for the reception and removal of workpieces and to close for clamping a workpiece between them, said dies in both the open and closed positions thereof being above the liquid level of said tank, means for force-quenching by circulating coolant liquid around a workpiece clamped between the dies, a container for liquid surrounding the lower die for maintaining coolant at a level above a workpiece on the lower die when the dies are opened subsequent to such forced quenching, said container having a pivoted bottom closure adapted to open to a downwardly inclined position wherein it constitutes a chute for discharging a workpiece from the container into said tank, and a transfer device for moving the workpiece from the lower die to a position directly above said closure.

According to another aspect of the invention the machine comprises a tank for coolant liquid, upper and lower dies adapted to open for the reception and removal of workpieces and to close for clamping a workpiece between them, said dies in both the open and closed positions thereof being above the liquid level of said tank, means for force-quenching by circulating coolant liquid around a workpiece clamped between the dies, a container for liquid surrounding the lower die for maintaining coolant liquid at a level above a workpiece on the lower die when the dies are opened subsequent to such forced quenching, said container also being adapted to maintain the workpiece submerged in the coolant liquid upon its removal from the lower die, a work transfer device for so removing the workpiece from the lower die, a gate separating the portion of the container in which the removed workpiece is disposed from the portion thereof immediately adjacent the lower die, and means to open and close the gate respectively to permit such removal of the workpiece and to maintain the liquid level around a workpiece in the firstmentioned portion of the container when the secondmentioned portion of the container is drained preliminarily to the placing of another workpiece on the lower die, and a closure for the container adapted to open to enable discharge of a workpiece into the tank 3,170,976 Patented Feb. 23, 1965 ice The preferred embodiment of the invention is shown in the accompanying drawings, wherein:

FIG. 1 is a front view of the machine partly in vertical section;

FIG. 2 is a fragmentary plan view showing the actuator for the pivoted bottom closure of the coolant container;

FIG. 3 is a fragmentary vertical section, on a larger scale than FIG. 1; and,

FIG. 4 is a view in a vertical plane perpendicular to FIG. 3 of a gate in the coolant container, and an actuator therefor.

The machine comprises a frame 10 having horizontal rods 11 along which a die support 12 is movable, in a path perpendicular to the plane of FIG. 1, to carry a lower die 13 thereon between a loading position near the front of the machine and a quenching position wherein it is vertically aligned with an upper die comprising concentric rings 14 and 15. The lower die is adapted to support a gear G which is placed on it when in loading position, and the upper die is adapted to engage the gear, when in working position, to clamp it to the lower die while it is being force-quenched with a liquid coolant. The upper die rings 14 and 15 are supported by ram 17 which contains hydraulic cylinders for applying a downward clamping pressure to them. The ram is raised and lowered by means of an hydraulic piston 18 operating in a cylinder 19 mounted on the frame. The ram is raised to enable the gear to be moved, on the lower die and support 12, from loading to force-quenching position, and to enable subsequent removal of the gear and return of the lower die with its support to loading position.

Quenching liquid is drawn from a sump in the frame by a suitable pump, not shown, and forced through passages 21 in the support 12 into the interior of a tubular shroud 22 which extends around the dies and is carried by ram 17. From the interior of the shroud the fluid passes over and under the gear G through the tooth slots of the latter and grooves in the die 13. It is then discharged, through a circular series of openings 23 between shroud 22 and a skirt 24- extending therearound, into a container which extends around the dies and the shroud.

This container, which is a part of the frame, has side walls 25 and bottom wall 26, the latter having an opening which is closed by the die support 12 when in its rearward or quenching position. When the support is forward, in loading position, fluid may drain through the opening into the sump therebelow. The front wall of the machine, which also is the front Wall of the container, has an opening 27 to pass the gear G as it moves between its loading and quenching positions. When the gear is in quenching position the opening is closed by a vertical gate 28 actuated by a piston 29 which operates in a cylinder 31 carried by the frame. The gate, when lowered to its closed position shown, seats on the upper forward part of support 12. At times when the force-quench liquid is being pumped, and the opening in bottom wall 26 is closed by support 12, the liquid in the container is maintained at a level above the gear G by a gate 32 which is adjustable, as permitted by elongated slots 33 for fasteners which secure it to one side wall 25. Liquid spilling over gate 32 returns to the sump through a suitable passageway, not shown. Slightly before each opening and closing of front gate 28, a rear gate (not shown) opens and closes, respectively, such opening of the rear gate allowing fiuid to drain from the container and hence preventing it from flooding the front of the machine when gate 28 is opened.

After the quenching of the gear G between dies 13-15, the forced circulation of coolant is stopped, the clamping pressure exerted by hydraulic cylinders in ram 17 is released, the dies are operated by raising of the ram by piston 18, and the gear is grasped by unloader jaws 34,

FIGS. 1 and 2, and moved substantially horizontally, into position G-2, above an opening 35 in container bottom wall 26. Jaws 34 are pivoted on axes 36 to a slide 37 and are moved to open position about these axes by springs,

not shown. Arms 38 rigid with the jaws are moved apart,

to close the jaws, for gripping a gear, by a taper 39 which is actuated by a piston 40 operating in a cylinder in the slide. In the position of the piston and taper shown in FIG. 1, wherein the piston is held to the left by a spring 41, the jaws are closed. Upon movement of the piston to the right by hydraulic pressure, the jaws are opened to release the gear onto bars 42 on a plate 43 which constitutes a closure for opening 35. The slide 37 is moved horizontally to transfer the gear from position G to position G-2 by a piston 44, operable in an hydraulic cylinder 45 on the frame.

As soon as a gear is transferred to position G-2, a vertical gate 46, FIGS. 1, 3 and 4, is raised, to the position thereof shown in broken lines, to divide the container into a chamber above the opening 35, designated 47, and separate chamber adjacent the dies. This enables the die support 12 to move forwardly to receive another gear, which causes the latter chamber to be drained, while a gear in chamber 47 remains immersed in coolant. The gate 46 has secured thereto rods 48 which are slidable in a bracket 49 on the machine frame to guide it through a slot in bottom wall 26 of the container. The gate is actuated by a piston 53 through a lever 51, fulcrumed at 52 to a bracket 53 secured to the frame, and a pivoted link 54. The piston, which operates in a cylinder 55 secured to the frame, lowers the gate to open position only after the gear has been discharged from chamber 47, and the unloader jaws are ready to advance to receive another gear from die 13.

The discharge of a gear from chamber 47 occurs just before the end of the force-quenching of a following gear, and is effected by downward pivoting of closure 43 to the piston shown in full lines in FIG. 1, wherein it :onstitutes the upper part of a chute which delivers the gear to position G-3, FIG. 1, on an endless belt type :onveyor 56 in a quenching tank 57 which is adjacent to and in effect is a part of frame 10. The lower part of the :hute, designated 58, is carried by a box-like support 59 ;ecured to the frame 10. The conveyor preferably moves :ontinuously and carries the part slowly in a rearward ipwardly inclined path through the quenching liquid in :ank 57 and finally discharges it from the rear of the .ank at a level above the level 60 at which the liquid is maintained in the latter.

The closure 43 has a depending lug 61 pivoted on a od 62 whose ends are secured to levers 63, one at each aide of opening 35. These levers, which are symmetrical, tre fulcrumed at 64 to part 65 of frame 10. A yoke 66 )ivoted to the levers at 67 is rigidly secured to rod 68 of l piston 69. The latter operates in an hydraulic cylinder pivoted to the frameat 71. Each lever carries a pring-backed plunger 72 which urges clockwise motion )f the closure 43 about pivot rod 62. As shown in FIG. 2, the sides of the yoke are spaced widely enough to allow the closure to pass between them. In the position hown in full lines in FIG. 3, hydraulic pressure in the ight chamber of cylinder 70 urges clockwise motion of he levers 63 about fulcrums 64, holding the closure 43 irmly against the bottom wall 26 of the liquid conainer. Upon pressure reversal, pressure applied to the aft chamber of cylinder 70, moves the levers counterlockwise, pivoting the closure 43 to the downwardly inlined position shown in full lines in FIG. 1. In this osition the left end of the closure rests on lower chute ection 58 and the right end on the upper edge of suport 59. As this pivoting motion proceeds the springacked plungers 72 act to hold the closure against the uper edge of support 59, holding it nearly level for a time nd thereby preventing sliding of the gear to the left rhich might cause it to override the bottom wall 26 of he liquid container.

In order to prevent the gear traveling down the chute from overshooting the conveyor 56 and being damaged by impact with the left wall of the tank, a soft bumper bar 73, made of asbestos fibre impregnated with a synthetic rubber, is secured to the wall.

Upon loading of a heated gear on the die 13 when the support 12 is in loading position, and starting of the machines quenching cycle, operation is effected automatically by a control system which includes timers, for example a timer to control the duration of the forced quenching of the part between dies 13-16, and further includes a number of limit switches each of which signals completion of one phase of the operation. This arrangement of these switches and other parts of the control system is not a part of the present invention. However, by way of example, in FIGS. 1 and 3, there is shown a limit switch 74 actuated by piston rod 68 when the latter reaches the position wherein closure 43 is fully closed. The operating sequence may be summarized asfollows: With a hot gear in loading position and a forcequenched but still hot gear at G-Z in chamber 47, the support 12 moves into quenching position, ram 17 lowers, downward clamping pressure is applied to die rings 14, 15 and forced flow of coolant liquid is started. During the quenching the clamping pressure may be released and re-- applied a number of times as disclosed in patent application Serial No. 710,882, filed Jan. 24, 1958, by R. V. Adair and O. F. Bauer, now Patent No. 3,007,823, granted November 7, 1961. At a predetermined time prior to the end of the quenching operation, the closure 43 is opened, discharging the gear at (3-2 and the fluid in which it is immersed into the tank 57. The closure 43 then closes, conclusion of this motion resulting in actuation of limit switch 74, which causes the gate 46 to be lowered so that chamber 47 quickly fills with fluid discharging from openings 23. Shortly thereafter the forced quenching is concluded, clamping pressure on die rings 14, 15 is released, ram 17 is raised, the unloader 34, 39, 41, 44 operates to remove the force-quenched gear from die 13 and release it onto closure 43, the gate 46 is raised (closed), the rear gate and the front gate 28 are raised (opened), and the support 12 is moved forwardly to loading position.

The force-quenching between dies 13-15 is preferably carried out at such a rate of flow and is of such duration that the gear is hardened to an extent such that it will undergo no appreciable distortion during further cooling. Its temperature of about 830 C. when loaded on the machine, may be reduced to approximately 500 C. at the surface (an average temperature throughout the gear on the order of 600 C.) when it is removed to chamber 47. By reason of its immersion in coolant in this chamber until near the completion of force-quenching of a following gear, its average temperature at the time of its discharge down chute 43, 58 may be on the order of 330 C., at which it is substantially harder and hence better able to resist distortion by impact loads than at the time of its removal from the dies. Moreover, by reason of the resistance imposed by fluid in tank 57 and the resilient bumper 73, impact loads are small. By reason of the rapidity with which the gears travel down the chute upon opening of closure 43, and the large volume of liquid contained in and being discharged into chamber 47, the gears are maintained completely immersed from the time of their forced quenching until their removal from the liquid in tank 57 by the conveyor 56.

Having now described our improved quenching machine, and its mode of operation, what we claim as our invention is:

1. A quenching machine for gears and like workpieces, comprising a tank for coolant liquid, upper and lower dies adapted to open for the reception and removal of workpieces and to close for clamping a workpiece be tween them, said dies in both the open and closed positions thereof being above the liquid level of said tank,

means for force-quenching by circulating coolant liquid around a workpiece clamped between the dies, a container for liquid surrounding the lower die for maintaining coolant at a level above a workpiece on the lower die when the dies are opened subsequent to such forced quenching, said container having a pivoted bottom closure adapted to open to a downwardly inclined position wherein it constitutes a chute for discharging a workpiece from the container into said tank, and a work transfer device for moving the workpiece from the lower die to a position directly above said closure.

2. A machine according to claim 1 in which there is a gate between the portion of said container adjacent the closure and the portion thereof adjacent the lower die, and means to open and close said gate respectively to permit passage of a workpiece from the lower die to a position above the closure and to maintain the liquid level around a workpiece in the first-mentioned portion of said container when the second-mentioned portion of the container is drained to enable the placing of another workpiece on the lower die.

3. A quenching machine for gears and like workpieces, comprising a tank for coolant liquid, upper and lower dies adapted to open for the reception and removal of workpieces and to close for clamping a workpiece between them, said dies in both the open and closed positions thereof being above the liquid level of said tank, means for force-quenching by circulating coolant liquid around a workpiece clamped between the dies, a container for liquid surrounding the lower die for maintaining coolant at a level above a workpiece on the lower die when the dies are opened subsequent to such forcequenching, said container having an opening beneath said level for passing a workpiece, a chute leading from said opening for conducting such workpiece and coolant covering the same to the tank, and a work transfer device for moving a workpiece from the lower die to a position directly above said chute upon opening of the dies.

4. A machine according to claim 3 in which there is a conveyor in said tank for receiving workpieces from the chute and traveling them along the tank, and a yieldable pad secured to a wall of the tank at the side of the conveyor opposite to the discharge end of the chute for arresting motion of the workpieces as they move onto the conveyor.

5. A quenching machine for gears and like workpieces, comprising a tank for coolant liquid, upper and lower dies adapted to open for the reception and removal of workpieces and to close for clamping a workpiece between them, said dies in both the open and closed positions thereof being above the liquid level of said tank, means for force-quenching by circulating coolant liquid around a workpiece clamped between the dies, a container for liquid surrounding the lower die for maintaining coolant liquid at a level above a workpiece on the lower die when the dies are opened subsequent to such forced quenching, said container also being adapted to maintain the workpiece submerged in the coolant liquid upon its removal from the lower die, a work transfer device for so removing the workpiece from the lower die,

a gate separating the portion of the container in which the removed workpiece is disposed from the portion thereof immediately adjacent the lower die, and means to open and close the gate respectively to permit such removal of the workpiece and to maintain the liquid level around a workpiece in the first-mentioned portion of the container when the second-mentioned portion of the container is drained preliminarily to the placing of another workpiece on the lower die, and a closure for the container adapted to open to enable discharge of a workpiece into the tank.

6. A quenching machine for gears and like workpieces, comprising a frame providing first and second quenching chambers, means including a pump for supplying quenching liquid to said chambers, upper and lower dies adapted to hold a workpiece in the first chamber, said dies being adapted to open for the reception and removal of workpieces and to close for clamping a workpiece between them, a first gate adapted when open to admit a workpiece to said first chamber and adapted when closed to maintain quenching liquid in the chamber at a level above a workpiece held by the dies, a second gate separating said chambers and adapted when closed to maintain liquid in the second chamber also at a level above a workpiece held by the dies and when open, subsequent to openings of the dies, to allow transfer or" a workpiece from the lower die in the first chamber to the second cham er beneath said liquid level, and a work transfer mechanism adapted to effect such transfer when the first gate is closed and the second gate is opened, whereby, upon such transfer and subsequent closing of the second gate, the workpiece may remain immersed in liquid in the second chamber While the first chamber is emptied and the first gate opened to enable the admission of a following workpiece to said first chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,385,480 Turtle July 26, 1921 2,074,312 Schraishuhn Mar. 16, 1937 2,822,162 Bastress Feb. 4, 1958 2,860,077 Adair et al. Nov. 11, 1958 2,907,858 Distler Oct. 6, 1959 

1. A QUENCHING MACHINE FOR GEARS AND LIKE WORKPIECES, COMPRISING A TANK FOR COOLANT LIQUID UPPER AND LOWER DIES ADAPTED TO OPEN FOR THE RECEPTION AND REMOVAL OF WORKPIECES AND TO CLOSE FOR CLAMPING A WORKPIECE BETWEEN THEM, SAID DIES IN BOTH THE OPEN AND CLOSED POSITIONS THEREOF BEING ABOVE THE LIQUID LEVEL OF SAID TANK, MEANS FOR FORCE-QUENCHING BY CIRCULATING COOLANT LIQUID AROUND A WORKPIECE CLAMPED BETWEEN THE DIES, A CONTAINER FOR LIQUID SURROUNDING THE LOWER DIE FOR MAINTAINING COOLANT AT A LEVEL ABOVE A WORKPIECE ON THE LOWER DIE WHEN THE DIES ARE OPENED SUBSEQUENT TO SUCH FORCED 